Digital images or 3D visualizations often need to be augmented with information that assists the viewer in understanding what is portrayed or that provides additional knowledge. The data representation of such descriptive metadata is a challenging task since digital media can be stored in various forms each of which provides, if at all, its own specific method for integrating its assigned metadata. The author analyzes existing techniques and intro­duces new approaches to store a digital medium, for example a digital image, and additional information associated with that medium, for example...